This is a partially finished chart looking at combined SAT scores of Bergen County high schools in 2009 and the median income of the town based on 2000 census figures. As the money goes up, the scores go up.
The two outliers on the bottom are towns that have expensive homes, but the kids are all shipped out to private schools.
I omitted two towns that had median incomes in the millions. I haven't finished coding about 15 towns.
I bet if I looked at 8th grade test scores, I would find an even tighter correlation. There are many regional high schools in the area, which might combine towns of differing SES levels.
I'm walking away from the Excel worksheet for a while. Steve gave me a bug that is making the rounds at his office, and I want to sit in the sun for a half hour before the kids get home.